Comparative genomic hybridization in epithelioid sarcoma

Background Epithelioid sarcoma is a rare mesenchymal neoplasm of unknown histogenesis. Data on genome-wide surveys for chromosomal aberrations in epithelioid sarcoma are limited. Objectives To investigate genetic aberrations in epithelioid sarcoma. Methods We analysed seven cases of epithelioid sarcoma (classic type, three cases and proximal type, four cases) by comparative genomic hybridization (CGH), and correlated findings with the results of additional immunohistochemical study. Results and conclusions CGH analysis showed DNA copy number changes at one to five different genomic sites in six of seven cases (86%). The majority of the changes were gains. The most frequent gain was at 22q (six cases). Other recurrent changes include gains of 12q24-qter (four cases), 17 (four cases), and 5q32-qter (three cases). High-level homology was seen in chromosomal aberration in both types. In addition, expression of interleukin-2 receptorbeta, located in 22q, was revealed by immunohistochemical method in six cases with gain of 22q, suggesting it may play a role in epithelioid sarcoma tumorigenesis.